Browsing by Author "ABDUL RASHEED, V"
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ThesisItem Open Access BIOLOGY AND MANAGEMENT OF SOUTH AMERICAN TOMATO LEAF MINER, Tuta absoluta (Meyrick) (Lepidoptera : Gelechiidae)(Acharya N.G. Ranga Agricultural University, 2018) ABDUL RASHEED, V; KOTESWARA RAO, S.R.The present investigations on “Biology and management of South American tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera : Gelechiidae)” were carried out in Department of Entomology, S.V. Agricultural College, Institute of Frontier Technology (IFT), Regional Agricultural Research Station (RARS), Tirupati and Yellampalli village, Kalikiri mandal, Chittoor district of Andhra Pradesh during rabi seasons of 2016-17 and 2017-18. Roving surveys on the incidence of South American tomato leaf miner, T. absoluta in major tomato growing mandals of Chittoor district during rabi 2016-17 and 2017-18 revealed that the mean per cent T. absoluta infested plants, leaflets and damaged fruits of tomato ranged from 51.37 to 66.12, 24.99 to 34.25 and 25.00 to 36.12, respectively. The mean per cent T. absoluta infested plants, leaflets and fruits of tomato were maximum in Kalikiri mandal (66.12%), (34.25%) and Vayalpadu mandal (36.12%) respectively, while minimum in Kalakada (51.37% infested plants), Madanapalli (24.99% infested leaflets), (25.00% damaged fruits) mandals. Mirid bug, Nesidiocoris tenuis (Reuter) nymphs and adults were found predating on eggs, first and second instar larvae of T. absoluta. The mean number of N. tenuis nymphs and adults per plant during rabi 2016-17 and 2017-18 ranged from 1.04 to 1.45. Maximum population was recorded in Vayalpadu mandal (1.45/plant) whereas minimum in Kalikiri mandal (1.04/plant). xxi Studies on the biology of T. absoluta revealed that the duration of egg, first, second, third and fourth instar larvae was 4.14 ± 0.35, 2.08 ± 0.28, 2.75 ± 0.65, 3.56 ± 0.56 and 3.86 ± 0.64 days, respectively. The total larval period of T. absoluta ranged from 10 to 14 days with a mean of 12.25 ± 2.13 days. The pupal period lasted for 6 to 9 days with a mean of 7.81 ± 0.75 days. Adult longevity on an average was 7.45 ± 1.32 days in case of males whereas 14.75 ± 1.16 days for females. The total development period of T. absoluta ranged from 22 to 27 days with a mean of 24.19 ± 1.37 days. Studies on morphometrics of T. absoluta found that the average length and breadth of egg, first, second, third and fourth instar larvae were 0.48 ± 0.05 and 0.27 ± 0.07 mm, 1.51 ± 0.07 and 0.19 ± 0.02 mm, 2.66 ± 0.04 and 0.39 ± 0.12 mm, 4.22 ± 0.06 and 0.64 ± 0.03 mm and 7.59 ± 0.09 and 1.15 ± 0.04 mm, respectively. The length and breadth of pupa were 4.13 ± 0.24 and 1.06 ± 0.14 mm, respectively. The mean length and breadth of adults were 10.71 ± 0.29 and 1.69 ± 0.10 mm, respectively. In age specific fecundity life table study of T. absoluta the net reproductive rate (R0), intrinsic rate of increase (rm), mean generation time (Tc), corrected generation time (T), finite rate of increase (λ) and weekly multiplication of population (7) were R0 40.18 individuals per female, 0.19 (female progeny/female/day), Tc= 30.16 days, T=28.94 days, λ= 1.20 and λ7 =35.83, respectively. Molecular characterization of T. absoluta larvae collected on tomato and brinjal from different states revealed that all populations viz., Andhra Pradesh, Telangana, Karnataka and Himachal Pradesh were grouped under single cluster and was more closely related while the population from Tamil Nadu was somewhat distantly related with the four states T. absoluta population. The populations of T. absoluta of Andhra Pradesh and Karnataka showed 100 per cent identity to the barcode sequence of T. absoluta from East Africa (KU565720) while populations of Telangana were closely related to NCBI accessions sourced from East Africa (KU565720), Oman (KT452897) and Egypt (KY129659). The populations of Tamil Nadu, Himachal Pradesh were closely related to India (KY619687), Egypt (KY129659) and East Africa (KU565720), Oman (KT452897), Egypt (KY129659) populations, respectively. Molecular characterization of T. absoluta confirms that this pest spread rapidly and adapted to Indian climatic conditions. Screening of thirty tomato genotypes were carried out during rabi 2016-17 and 2017-18 to identify the source of resistance/susceptibility to T. absoluta. Among genotypes tested none was free from T. absoluta infestation. Based on total damage index, the tomato genotypes were categorized as moderately resistant (EC-620410, EC-620401, EC-620343, EC-164577, EC-538153, EC-620370, EC-631379, EC-620396, EC-631369 and xxii EC-620422), moderately susceptible (EC-165690, EC-249508, EC-567305, EC-620427, EC-620382, EC-620394 and EC-620392), susceptible (EC-620147, EC-620397, EC-620406, EC-620395, EC-164563, EC-521067-B, EC-620372, EC-620376, EC-165700, EC-538156 and EC-249514) and highly susceptible (EC-620433 and EC-160885) to T. absoluta. Among biophysical parameters, leaflet length and width found a significant positive correlation with infestation of T. absoluta on leaflets, fruits and larvae per compound leaf whereas leaflet thickness, trichome density and SPAD chlorophyll meter reading (SCMR) were found to have a significant negative correlation. Correlation studies of biochemical constituents with infestation of T. absoluta on leaflets, fruits and larvae per compound leaf revealed that the phenol content in the leaves was found to be negative and significant whereas proteins, reducing sugars were found to be positive and significant in tomato genotypes. The lycopene content in fruits was found to be positive and non significant association with the damage on fruits by T. absoluta in tomato genotypes. Evaluation of certain insecticides against T. absoluta on tomato leaves during rabi 2016-17 and 2017-18 found that the highest mean per cent reduction over untreated control was recorded in chlorantraniliprole (61.17%) treated plot followed by cyantraniliprole (58.64%) and emamectin benzoate (52.87%) while lowest was recorded in fenvalerate (28.24%) followed by lambda cyhalothrin (30.29%) and imidacloprid (33.22%) treated plots. Evaluation of certain insecticides against T. absoluta on tomato fruits during rabi 2016-17 and 2017-18 revealed that the lowest mean per cent infestation on fruits was recorded in chlorantraniliprole (18.51%) treated plot followed by cyantraniliprole (25.30%), flubendiamide (26.37%) and emamectin benzoate (29.53%).The highest mean per cent infestation on tomato fruits was recorded in untreated control (61.53%) followed by fenvalerate (42.80%) and lambda cyhalothrin (41.18%).